Nowadays, our tap water in daily living is full of pesticides, chemical constituents and varieties of impurity, owing to rivers being polluted by industrial and household waste water, garbage and livestock excretion caused by modern industrialization as well as lacking of environmental protection. Although it has been purified in the public waterworks treatment by chlorinating, such water with some remaining chloride residuals becomes harmful to the health of a human being. Thus, civil consumers usually obtain their potable water from purification equipment they've purchased. Many households even have their own purification equipment installed at home on the shower to get a better quality of bathing water. The principle herewith is to adsorb or remove pesticides, chemical constituents and varieties of impurity in the water by means of embedded adsorbents such as activated carbon, metallic sulfite, KDF therein.
Presently, there are some conventional devices of hand held showerheads with filter assemblies such as the devices in the prior art of US Pat. Nos. 4,107,046; 6,016,977 and 6,270,023. Though these devices can filter the shower water efficiently in some degree, it will fail at the critical point of filter assembly (or service life) after operating for a certain period of time, depending on the specified maximum quantity of water filtered by accumulated flux therethrough.
For example, if a maximum quantity of water that can be filtered is 1500 gallons, then such is the critical point of filter assembly. Once the filter assembly reaches this critical point, it will be spent and deteriorated, then lose its filtering function due to accumulated impurities. It can resume its filtrating ability only by replacing with a new filter. However, for those filters of devices in the current marketplace, the label or tag attaching thereon provided by vendors only specifies its critical point (or Service Life) in terms of quantity in gallon unit, neither the measuring instrument nor the tool thereof is provided by vendors.
Therefore, upon purchasing a new filter assembly, the consumer is always reminded by vendor to replace the filter in a half year or some other number of months. But if the consumer replaces the filter prematurely before reaching its critical point, it becomes wasteful as an increasing economic burden. To the contrary, if a consumer replaces the filter beyond its critical point, the filtering function of the filter may fail due to an abundance of accumulated dirt. Thus, the user of the purification equipment may get a filtered water whose quality is much dirtier and worse than that of tap water—without a malfunctioned filter, which ingested by a human being can severely jeopardize health even more.
However, the time for reaching the critical point of hand held shower head with a filter assembly is subject to differences of the number of users in each family. For example, if the average daily usage of water quantity for each person is 2 gallons, then the filter assembly, which is embedded in the hand held shower head, can be operated validly for 250 days in a family of 3 users; however, it can be only operated validly for 125 days in a family of 6 users. In other words, the aforementioned filter assembly of the prior art neither offers a feature of pre-alarm upon reaching its critical point nor having precise measurement control or record-keeping, having the consequences of missing replacement times and still continuing to use the malfunctioned filter, causing skin discomfort such as allergy or itchiness. Even more, the chronic exposure of chlorine on the skin may make a user susceptible to cancer. Obviously, the customary filter assemblies of the preceding prior art are neither practical nor ideal in effectiveness.